XmlSerializer.UnknownElement XmlSerializer.UnknownElement XmlSerializer.UnknownElement XmlSerializer.UnknownElement Event


當還原序列化期間,XmlSerializer 遭遇未知型別的 XML 項目時發生。Occurs when the XmlSerializer encounters an XML element of unknown type during deserialization.

 event System::Xml::Serialization::XmlElementEventHandler ^ UnknownElement;
public event System.Xml.Serialization.XmlElementEventHandler UnknownElement;
member this.UnknownElement : System.Xml.Serialization.XmlElementEventHandler 
Public Custom Event UnknownElement As XmlElementEventHandler 


下列範例會還原序列化的類別,名為Group從名為 UnknownElements.xml 檔案。The following example deserializes a class named Group from a file named UnknownElements.xml. 在類別中,沒有對應成員的檔案中找到的項目,是每當UnknownElement就會發生事件。Whenever an element is found in the file that has no corresponding member in the class, the UnknownElement event occurs. 若要嘗試的範例,請將下列 XML 程式碼貼入名為 UnknownElements.xml 的檔案。To try the example, paste the following XML code into a file named UnknownElements.xml.

<?xml version="1.0" encoding="utf-8"?>  
<Group xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">  
#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml::Serialization;
using namespace System::Xml;
using namespace System::Xml::Schema;

public ref class Group
   String^ GroupName;

public ref class Test
   void Serializer_UnknownElement( Object^ sender, XmlElementEventArgs^ e )
      Console::WriteLine( "Unknown Element" );
      Console::Write( "\t {0}", e->Element->Name );
      Console::WriteLine( " {0}", e->Element->InnerXml );
      Console::WriteLine( "\t LineNumber: {0}", e->LineNumber );
      Console::WriteLine( "\t LinePosition: {0}", e->LinePosition );
      Group^ x = dynamic_cast<Group^>(e->ObjectBeingDeserialized);
      Console::WriteLine( x->GroupName );
      Console::WriteLine( sender );

   void DeserializeObject( String^ filename )
      XmlSerializer^ ser = gcnew XmlSerializer( Group::typeid );

      // Add a delegate to handle unknown element events.
      ser->UnknownElement += gcnew XmlElementEventHandler( this, &Test::Serializer_UnknownElement );

      // A FileStream is needed to read the XML document.
      FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
      Group^ g = dynamic_cast<Group^>(ser->Deserialize( fs ));

int main()
   Test^ t = gcnew Test;

   // Deserialize the file containing unknown elements.
   t->DeserializeObject( "UnknownElements.xml" );
using System;
using System.IO;
using System.Xml.Serialization;
using System.Xml;
using System.Xml.Schema;

public class Group{
   public string GroupName;

public class Test{
   static void Main(){
      Test t = new Test();
      // Deserialize the file containing unknown elements.
   private void Serializer_UnknownElement(object sender, XmlElementEventArgs e){
      Console.WriteLine("Unknown Element");
      Console.WriteLine("\t" + e.Element.Name + " " + e.Element.InnerXml);
      Console.WriteLine("\t LineNumber: " + e.LineNumber);
      Console.WriteLine("\t LinePosition: " + e.LinePosition);
      Group x  = (Group) e.ObjectBeingDeserialized;
      Console.WriteLine (x.GroupName);
      Console.WriteLine (sender.ToString());
   private void DeserializeObject(string filename){
      XmlSerializer ser = new XmlSerializer(typeof(Group));
      // Add a delegate to handle unknown element events.
      ser.UnknownElement+=new XmlElementEventHandler(Serializer_UnknownElement);
      // A FileStream is needed to read the XML document.
     FileStream fs = new FileStream(filename, FileMode.Open);
     Group g = (Group) ser.Deserialize(fs);
Imports System
Imports System.IO
Imports System.Xml.Serialization
Imports System.Xml
Imports System.Xml.Schema
Imports Microsoft.VisualBasic

Public Class Group
   Public GroupName As String 
End Class

Public Class Test
   Shared Sub Main()
      Dim t As Test = new Test()
      ' Deserialize the file containing unknown elements.
   End Sub

   Private Sub Serializer_UnknownElement _
   (sender As Object , e As XmlElementEventArgs)
      Console.WriteLine("Unknown Element")
      Console.WriteLine(ControlChars.Tab & e.Element.Name + " " & e.Element.InnerXml)
      Console.WriteLine(ControlChars.Tab & e.LineNumber & ":"  & e.LineNumber)
      Console.WriteLine(ControlChars.Tab & e.LinePosition & ":"   & e.LinePosition)
      Dim x As Group = CType( e.ObjectBeingDeserialized, Group)
      Console.WriteLine (x.GroupName)
      Console.WriteLine (sender.ToString())
   End Sub
   Private Sub DeserializeObject(filename As String)
      Dim ser As XmlSerializer = new XmlSerializer(GetType(Group))
      ' Add a delegate to handle unknown element events.
      AddHandler ser.UnknownElement, _
      AddressOf Serializer_UnknownElement 
      ' A FileStream is needed to read the XML document.
     Dim fs As FileStream  = new FileStream(filename, FileMode.Open)
     Dim g  As Group = CType(ser.Deserialize(fs),Group)
   End Sub
End Class


根據預設之後呼叫,Deserialize方法,XmlSerializer會忽略未知型別的 XML 屬性。By default, after calling the Deserialize method, the XmlSerializer ignores XML attributes of unknown types. 不過,您可以使用這個事件來處理這種節點型別。However, you can use this event to handle such node types.


如果XmlAnyElementAttribute套用至傳回陣列的欄位XmlElement物件時,所有未知的項目會收集陣列中。If the XmlAnyElementAttribute is applied to a field that returns an array of XmlElement objects, all unknown elements are collected in the array. 在此情況下,UnknownElement事件不會發生。In that case, the UnknownElement event does not occur.